Electrophotographic image recording is a well-known and commonly used method of coping or printing documents. Electrophotographic image recording typically is performed by exposing a substantially uniformly charged photoreceptor to a light image of a document. In response to the light image, the photoreceptor discharges to create an electrostatic latent image of the document on the surface of the photoreceptor. Toner particles are then deposited onto the latent image to form a toner image, which is transferred from the photoreceptor, either directly or after one or more intermediate transfer steps, onto a recording substrate, such as a sheet of paper. The transferred toner image is then fixed or fused to the recording substrate using heat and/or pressure. The photoreceptor surface is then cleaned of residual developing material and recharged in preparation for the creation of another image.
This process can be used to produce either black and white images or color images. Color images may be produced by repeating the above process once for each color used to make the color image. For example, the charged photoconductive surface may be exposed to a light image that represents a first color, such as cyan. The resultant electrostatic latent image can then be developed with cyan toner particles to produce a cyan image that is subsequently transferred to an intermediate transfer member or a recording substrate. The process can then be repeated for a second color, such as magenta, then a third color, such as yellow, and finally a fourth color, such as black. Each color toner image may be transferred to the intermediate transfer member or recording substrate in superimposed registration, to produce the desired composite toner powder image. In systems using an intermediate transfer member, successive toner images are transferred in superimposed registration from the photoreceptor onto the intermediate transfer member. Only after the composite toner image is formed on the intermediate transfer member is that image transferred and fused onto the recording substrate. In the alternative, the toner images may be successively transferred onto the recording substrate, and then fused.
Toner particles are usually provided to the photoreceptor as part of a developer. The most common developers are dry powder toners, which typically comprise toner particles and carrier granules. Toner particles triboelectrically adhere to the carrier granules until the toner particles are attracted onto the latent image. An alternative to dry, powder developers is liquid developers. In liquid developers, or liquid inks, toner particles are dispersed in a liquid carrier. When liquid developers are used, both the toner particles and the liquid carrier brought into contact with the electrostatic latent image. The liquid carrier is then removed, for example by blotting or evaporation, leaving the toner particles on the photoreceptor surface.
Fusing can occur after transfer of the toner image to the recording substrate, or transfer and fusing can simultaneously occur in a transfuse process. In either arrangement, the recording substrate is fed into a fusing nip where a combination of fusing members, such as by transfuse or fusing belts or rollers, apply heat and pressure to the toner image and the recording substrate to fix or fuse the toner image to the recording substrate. During the fusing process, toner particles from the toner image and debris from the substrate can adhere to the fusing member. Adhered toner particles and other contaminants can transfer from the fusing member to subsequent documents, resulting in print defects. In addition, toner particle build-up can decrease the operational life of the fusing member. Thus, it is preferred that fusing members be cleaned to remove particulate debris, such as adhered toner particles, dirt and fiber, that can affect final print quality.
Most current fusing systems include a system for automatically cleaning the fuser roll and/or supplying the fuser roll with a lubricant or release agent. For example, the surface of the fuser roll may be cleaned and/or lubricated by means of a web that is pressed against the surface of the fuser roll at a location generally away from the nip formed by the pressure and fuser rolls. The webs of known systems provide either a textured surface or a tacky or sticky surface for removing adhered toner particles from the fuser roll. The web may also provide amounts of lubricant or release agent to the fuser roll. As is well known, the function of the release agent is to prevent sheets of paper that pass through the fuser nip from sticking to the surface of the fuser roll, thus preventing the stuck paper sheets from causing a paper jam. In addition, the release agent minimizes the amount of toner that sticks to the fuser roll rather than remaining on the paper.
Generally, the web is drawn from a replaceable supply roll and is moved at a reasonably slow rate relative to the movement of the fuser roll, causing the surface of fuser roll to rub against a small area of the web. The relatively slow motion of the web provides friction to the fuser roll surface and provides a supply of clean web at a reasonable rate. A typical ratio of surface speeds, for example, in a 60 page-per-minute printer, is approximately 300 mm per second for the outer surface of the fuser roll; in contrast, the speed of the web is 2 to 3 mm per minute. Typically, the web is withdrawn from a supply roll and pulled by and wound on a take up roll.
However, there remains a need for improved systems, apparatuses and methods for cleaning residual toner particles and other debris from fuser rolls of electrophotographic imaging systems.